'''
    为了统计学生人数，给 Student 类增加一个类属性，每创建一个实例，属性自动增加
'''
class Student():
    count = 0
    def __init__(self,name):
        self.name = name
        Student.count += 1

new_student = Student('jenny')
new_student = Student('bob')
print('Total number of students：' + str(Student.count) + '.')
